3D Anisotropic Full Waveform Modeling with an Enhanced OASES Workflow for Complex Source-receiver Geometries

We examine the OASES program code as a potential alternative to wave propagation modeling techniques in microseismic research. We provide an overview on the mathematics and the numerics of OASES, which uses wavenumber integration and the Direct Global Matrix solution technique to model wave propagation in horizontally layered media. In order the increase the usability of OASES for complex source-receiver geometries, we introduce a predominantly automatic enhanced OASES workflow. This workflow is applied to two three-dimensional anisotropic full waveform modeling tests. In the first test, we compare synthetic seismograms computed with OASES to results from two previous studies by the PHASE consortium, which modeled wave propagation with a ray tracing algorithm and the finite difference method respectively. The comparison shows an excellent consistency between all three modeling techniques. The second test compares synthetic seismograms computed with OASES to picked wave arrivals from a microseismic dataset from the Horn River Basin in Canada. The consistency between the modeled and picked wave arrivals is satisfactory for most events, but indicates the necessity of further improvements on the provided velocity model.